From everything I read, I think you can just plant them in the mud in your pond but most say leave them in pots as they can spread and be invasive over time (even though they will 'jump' the pot over time anyway). I just potted the ones I was given by my brother earlier in the spring today--they have been floating around in our koi pond and living but not blooming. If they are in the pot, you can get fertilizer tabs and stick it down in the pot near the roots. Of course, I am learning myself and not an expert in the least so am afraid I'm not much help. I used topsoil mixed with some fine mulch and a bit of Black Kow in the pot with sand on the top followed by pebbles. They are in the upper end of our pond where the comet goldfish are. Koi, they say, can uproot your potted plants.

Hi
I have almost no experience with hardies as i grow only tropicals but the method is about the same. I would keep them potted at least for the first few seasons to see what type of growth they produce . Place something underneath to bring the pot near the surface as growth progresses lower the depth. i use expanded clay (Kitty litter, oil dri) as a media .Fruit tree spikes pushed into the clay as growth stabilizes.. By summers end you should be able to have them on the bottom with enough depth for the winter,
I certainly wouldn't plant ANYTHING directly into the bottom almost all water plants are incredbibly invasive though I would bet less so with a winter dormancy.. Good luck gary

Thanks for the advice. I'm going to repot the plants in larger containers then sink them to about 2ft. for now. later in the fall we can sink them deeper for winter. Our pond is so beautiful naturally and the lilies will add another dimension to it. Hope it works.

I planted my hardy lily in an oil-changing pan with dirt covered by rocks. I made a macrame holder for it so I can lift it to put the plant tabs in. I stick them well into the dirt so the fertilizer doesn't leach into the pond and feed the algae.

My pond is 2 1/2 feet deep and the lily lives at that depth year round (Zone 4). If you look at lilies in nature, some live in less than that depth and survive freezing. I agree with you, the 6 - 8 foot depth is too deep. According to what I have read, 2 - 3 feet is the deepest you want to go. I don't know if that is true.

Your pond will be lovely with the lilies in it.

Do you know the names of the waterlilies you purchased?

Two feet is actually shallow for hardy waterlilies unless they are dwarf or miniature.

The pads will lengthen overnight to reach the surface though I would not plant them six feet deep right away, you can do three or four feet.

Some bare root and tie rocks to the rhizomes and drop into mud bottomed ponds.

There are some with aggressive growth but most are not a problem. If you know the names, I can tell you if they may become a problem or not. How big your pond is would help too.

Waterlilies in a natural mud bottomed pond generally do not need fertilizer. The muck on the bottom is their natural habitat and full of nutrients for them.

It is in our sterile liner ponds that they need fertilizer which is tablet form and pushed into the soil.

You could put the waterlily in a burlap or bag made from landscape fabric with clay soil.The bag would keep the soil from going into the pond and make it easier to drop the lilies deeper in the winter. Once the lilies have lots of leaves you can lower them deeper in the pond. They will overwinter fine at the bottom of your pond. I like the laquana fertilizer spikes as they work all season long but like Horton said in a natural pond you wont need the fertilizer.

Mine are hardy and in a preformed pond and I fertilize with Job tomato spikes, one per plant about every 2 months during the growing season, but again, it's a preformed pond and only about 20" deep

I have had water lilies for several years & here in zone 7; I just sink the pots to the bottom (30 inches) in the Fall. They not only have survuved but each spring I have to take the hatchet to the huge root masses & chop them up to start new & to give away to others. Just plain old white pond lilies but does fine over-winter here. Would like to get a start of a red or yellow one some time but pond really not big enough though for much more. Never realized how big & tough those roots can get!!

Nature knows what it's doing. I started out with lilies in pots and I'd pull them up in the fall to trim and repot. After a couple years a strange thing happened. The pond was covered with lilies, but when I pulled the pots up there was nothing alive in them. The lilies had abandoned the pots and established themselves in the bottom. Now I leave them alone and they come up every year.

Hardy waterlilies become large plants in a few months and need a substantial weight of pot to root onto and anchor them.

As small plants to start with, you want to keep an eye on them in a foot of water in case destructive grazing critters start destroying them.

Koi, carp, ducks may wreck the roots and shoots, turtles may snip every stem and destroy the plant if it's out of sight

As confidence in the plants progress continues, you can think about shuffling a well potted waterlily to what seems a suitable depth a foot deeper at a time.

I don't see any point in planting them too deep if there is a convenient shallower depth to set them in as then they will be unrealistic to sort out if they become a problem in the future.

A realistic depth being, how deep can you reach and still be able maneuver, chop, hack, wrestle a bulky large plant that may be well lashed to the bottom of the pond

It's perty easy to wrap any suitable type of fertiliser in a small sealed plastic wrap and prod it below the crown, the point where shoots and blooms come up from. Poke a small hole so the water dissolves and releases the fertiliser slooow.

There are hardy waterlilies with mature sizes from a two foot spread to twenty. They do not all grow huge with massive rhizomes that you have to chop with an axe...